[gnome-sdk-images/gnome-3-24] Update to latest stable gtkwebkit

[Alexander Larsson <alexl src gnome org>]

commit a8fef256c69a3ee5677dc737e710cac9779ce935
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Aug 16 15:07:09 2017 +0200

    Update to latest stable gtkwebkit

 org.gnome.Sdk.json.in |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index d74f254..3561f51 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -544,8 +544,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://webkitgtk.org/releases/webkitgtk-2.16.2.tar.xz";,
-                    "sha256": "5ef689a202eb2b71141efbe8b7b53288adced90790f9f08df6e0a2ec1809f252"
+                    "url": "https://webkitgtk.org/releases/webkitgtk-2.16.6.tar.xz";,
+                    "sha256": "fc23650df953123c59b9c0edf3855e7bd55bd107820997fc72375811e1ea4b21"
                 },
                 {
                     "type": "patch",